Adjusting means for projection objectives



H. N. OTT AND F. H. BUFTON.-

ADJUSTING MEANS FOR PROJECTION OBJECTIVES. APPLICATION FILED Nov,I3,'I9I9.

1 .3f-11,667. Patented June 1, 1920.l

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UNITED STATE i *fr-#Artnr OFFICE. Y

HARVEY N. OTT AND FRANK H. BUFTON, OF BUFFALO, VNE YORK, ASSIGNORS TO*SPENCER LENSy CO., 0F BUFFALO, NEW YORK.

ADJUSTING MEANS FOR PROJECTION OBJECTIVES.

Specification of Letters Patent.

Patented J une 1, 1920.

Original application filed October 31, 1916, Serial No. 128,699. Dividedand this applieatonijled No-y vember is, 1919.' serial ivo. 337.772.

for projection objectives and particularly for projection objectivessuch as are used in projection apparatus for projecting the images ofopaque objects. 4

This application is a division of our application for Patent filed Oct.31, 1916, Serial No. 128,699. j

The objects of the invention are to provide adjusting means for opaqueprojection objectives or other objectives which works easily and enablesthe ready adjustment of the objective to the desired position; toprovide adjusting means for such objectives which willinsure the holdingof the objective in the adjusted position, and to improve adjustingmeans of this sort in other respects hereinafter set forth. i

In the accompanying drawings:

Figure 1 is a side elevation partly in section of a projectionapparatus, having an opaque objective which is provided with adjustingmeans constructed in accordance with the invention.

Fig. 2 is a sectional plan View, enlarged, on line 2-2 Fig. 1 of theadjusting means for the objective for the opaque objects.

Fig. 3 is a sectional elevation thereof on line 3-3 Fig. 2.

An adjusting means for projection objecn tives constructed in accordancewith one embodiment of the invention is shown in the drawings associatedwith a projection apparatus which will be briefly described.

A represents the casing or light chamber of the apparatus. B representsthe objective for the transparent lantern slides or objects, and Crepresentsthe opaque projection objective. The objective B for thelantern slides is arranged at the front end of the casing and the otherobjective C at the top of the casing. F represents an inclined mirror orreflector for directing the light rays forwardly from the objective C tothe screen. G is an incandescent lamp or other usual source of light,which may be supported on a slide or carriage 11 arranged to slide intoand out of the casing.

16 represents'a mirror for reflecting light from the lamp onto theopaque 'object or post.

card, which is supported face upward at the bottomof thecasing in" aholder or device 88. The mirror is secured in a pivoted ring 17 whichVis provided with journals 17a, so that the mirror may be swung fromthe'position shown in. full lines in Fig. 1 tothe.

position shown indotted lines. In this po-` sition the light from thelamp G is permitted to pass directly into the objectivev B.

The invention does not relate tothe construction of these parts and theymay be of any usual or suitable construction.

he projection objective C for the post Vcards or opaque objects isadjustable vertithem from being held stationary in the ad-vv justedposition unless the friction of the adjusting mechanism is so great asto be objectionable in use. Onaccount of the large diameter of thelenstube, itVv is also liable to bind in its guide andmake the'adjusting mechanism work hard. In order to overcome these objectionsand vprovide means which can be readily and easily op' eratedV foradjusting the 'objective and Vwhich will insure the holding of the samein its adjusted position, the following construction is employed: 52represents a vertical plunger or post arranged to slide vertically in acylinder or tubular guide 53 fixed in any suitable manner on top of thecasing A at one side of the objective. The post is provided at one sidewith a toothed rack 54, and an adjusting shaft 55 suitably journaled onthe guide cylinder is provided with a pinion 56 meshing with the rackfor raising and lowering the post. Any other suitable means foradjusting the post may be substituted. The adjusting shaft is providedat its outer end with a finger wheel or other means for turning it. Theguide cylmit it to be contracted on the post sulficiently to create thedesired friction to oppose the movement of the post. The split f portionof the guide tube, as shown, is provided with vears or lugs 58 connectedby screws for contracting it on the post. The post is made hollow and aspring 59 inclosed therein between the top of the casing and the upperend of the post tends to lift the post and the: parts connectedtherewith and to yieldingly resist the descent of the same. The post isconnected to the lens tube of the objective C, or otherwise associatedtherewith in any suitable manner, so thatthe weight of the lens tube andthe parts thereon is carried by the adjusting post, and the objective isadjusted by the adjustment of the post. As shown, a connecting ring 6()surrounds the lens tube below a lipY or collar.

6l thereon and is provided with a split clamping portion which embracesthe upf,

per end of the adjusting post and is clamped thereon as by means of ascrew 62. rllhis clamp can be readily secured to the post at therequired elevation with reference to the lens tube. By this arrangementthe spring 59 tends to lift the post and the objective connected theretoand to oppose the descent of these parts. By using a spring whichsubstantially counterbalances the weight of the post and parts connectedthereto, the adjusting gear can be turned easily and 'the parts willnevertheless be supported in the adjusted position without thelikelihood of lowering-from this position under the force of gravity.Since the adjusting post is of small diameter it is not apt to bind inits guide cylinder and it properly guides the objective. Thisarrangement also enables the adjusting shaft to be placed lower in amore convenient position than it could be placed on the objective guidetube.

Ve claim as our invention:

l. In a projection apparatus, the combination of a projection objective,a guide in which said objective is arranged to slide up 2. In aprojection apparatus, the combination of a projection objective, a guidetube in which said objective is arranged tol slide up and down, a guidetube arranged at one side of said objective, a hollow post arranged toslide up and down in said guide tube, a spring located in said hollowpost and acting to lift the same, means for adjusting said post up anddown, and means connecting said post to said objective for causing theobjective to move with the post.

8. In a projection apparatus, the combination of a projection objective,a guide tube in which said objective is arranged to slide up and down, aguide tube arranged at one side of said objective, a hollow postarranged to slide up and down in said second mentioned guide tube, aspring located in said hollow post and acting to lift the same, meansfor adjusting said post up and down, and a connecting device connectedto said objective and adj ustably secured to said adjusting post.

4. In a projection apparatus, the combination of a projection objective,a guide in v which said objective is arranged to slide for focusing` theobjective, a second,l guide arranged parallel with said lirst guide atone side thereof, a post arranged to slide endwise in said second guide,a spring which tends to move said post in one direction, means foradjusting said post endwise, and means connecting said post' to saidobjective for causing the objective to move with the post. i

Witness our hands this 11th day of November 1919.

HARVEY N. OTT. FRANK H. BUFTON. lVitnesses ISABEL FAIRBURN, EDWARD E.Tnos'r.

